Gif Animation

GIF was one of the first two image formats commonly used on Web sites, the other being the black and white XBM. JPEG came later with the Mosaic browser.
The feature of storing multiple images in one file, accompanied by control data, is used extensively on the Web to produce simple animations. The optional interlacing feature, which stores image scan lines out of order in such a fashion that even a partially downloaded image was somewhat recognizable, also helped GIF's popularity, as a user could abort the download if it was not what was required.